This invention relates to a sliding roof for motor vehicles having a transparent rigid sliding cover, by means of which an opening in the roof can be selectively closed or can be at least partially exposed, as well as having a frameless inside cover lining that can be adjusted, at least in the closing direction, independently from the sliding cover and is guided at its lateral edges.
Sliding roofs of this type are known (U.S. Pat. No. 4,018,476 and U.S. Pat. No. 4,320,921), where the sliding inside cover lining consists of a molded plastic part. Especially in cases when the motor vehicle is parked in the sun while the sliding cover is closed, relatively high temperatures sometimes occur on the inside of the motor vehicle. The influence of the heat can result in deformation of the large-area, sliding inside cover lining, which may result in the sliding inside cover lining becoming jammed in its guides. This cannot be remedied in a satisfactory manner, even if the sliding inside cover lining is lock-beaded or provided with welded-on grid profiles.
The invention, therefore, has a principle object of creating a sliding roof of the initially-mentioned type where the sliding inside cover lining is formed in such a way that it requires low manufacturing expenditures, but is especially insensitive with respect to thermal and other stresses.
According to a preferred embodiment of the invention, this object is achieved by forming the sliding inside cover lining as a panel of sandwich-type construction having a core layer and a cover layer that is applied at least on one side of said core layer, and by squeezing the sandwich panel together in the area of its lateral edges in a manner forming guide edges.
It is known to use sandwich panels in motor vehicle construction. For example, DE-OS 28 45 708 describes a rigid motor vehicle roof having a sandwich panel, the exterior side of which forms the roof membrane, and the interior side of which forms the rigid inside roof lining. Flap-shaped front hoods made of sandwich panels are explained in DE-PS 29 34 430. A spoiler roof is known from DE-OS 31 10 698, where the sliding cover is developed as a sandwich component. However, so far, such sandwich panels have not been used for sliding inside cover linings of sliding roofs. Among other things, this is probably the result of the fact that sliding inside cover linings must be guided laterally and, for this guiding, only a very limited space is available in a vertical direction. Sandwich panels cannot be slid into the guides of the known types.
By means of the present invention, the inherent stability of the sandwich panels, while the weight is the same, is considerably increased as compared to molded plastic parts. Weighing the same and/or having the same overall height, such sandwich panels have a much higher stability and a considerably reduced tendency to expand and deform under the influence of heat. At the same time, the compression of the sandwich panel in the area of its lateral edges, according to the present invention, provides guide edges for the sliding inside cover lining, which fit into space-saving guides of the conventional type. The development of the guide edges by the squeezing of the sandwich panel is especially simple with respect to manufacturing. Suitable sandwich panels that can be compressed together are available commercially. At its bottom side and/or top side, the sandwich panel can be covered at random with few expenditures. The covering may take place during the manufacturing of the sandwich panel or later in the form of a separate working cycle. The sliding inside cover lining developed according to the invention, at the same time, results in improved muffling of noises.
In a further development of the invention, at least one of the layers of the sandwich panel has a pressure-reactive and/or thermoreactive plastic material which, when the sandwich panel is squeezed, develops a gluing activity. This ensures that, without additional manufacturing expenditures during the squeeze-shaping, stable and nondeformable guide ridges are obtained. The already relatively good muffling of noises by the sandwich panel sliding inside caover lining can be improved further by providing, especially the lower cover layer, with noise-reducing features. For example, the lower cover layer may expediently consist of flocks and/or foamed material and/or fabric, or can be flock-coated. A two-layer construction of the cover layer may also be provided, in which case, the lower layer consists of fabric and the upper layer consists of foamed material. Preferably, the lower cover layer, with respect to structure and/or shade of color, is matched in appearance to the rigid inside roof lining. The core layer may consist of rigid expanded plastics. Particularly high stabilities are obtained by means of a honeycombed core layer. In this case, the honeycombs may expediently consist of metal foil, such as aluminum foil or a plastic material, and may be at least partially hollow or filled, Suitable as fillers are especially rigid expanded plastics, synthetic resin or a composite material of synthetic resin and a fiberglass material.
Between the core layer and the respective cover layer, an intermediate layer may advantageously be provided which supplies the mutual connection between the core layer and the cover layer and/or provides a further stiffening of the sandwich panel. Preferably, the intermediate layer consists at least partially of a pressure-reactive and/or thermoreactive plastic material. In addition, the intermediate layer advantageously can supply at least part of the filler.
A gripping bowl may expediently be imbedded in the sandwich panel, in which case, the gripping bowl can be molded on or can be developed as a separately fastened part. The same is true for possible additional stops, catches or guide parts of the inside roof lining.
These and further objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, several embodiments in accordance with the present invention.